1. Field of the Invention
The present invention relates to a device for detecting a level of liquid contained in a vessel, and more particularly to a fuel level gauge for use in an automotive vehicle.
2. Description of Related Art
A fuel level gauge having a float floating on a surface of fuel in a fuel tank has been known hitherto. The float is connected to one end of an arm, and a permanent magnet is connected to the other end of the arm. The magnet is rotatably supported by a housing in the fuel tank. A magnetoresistive element is disposed to face the magnet to thereby detect an amount of magnetic flux passing through the magnetoresistive element. Since the amount of flux passing through the magnetoresistive element changes according to the fuel level in the fuel tank, the fuel level is detected based on the amount of the flux. An example of this type of fuel level gauge is disclosed in JP-A-2002-107205.
When the float floating on the fuel surface swings due to vibration of the vehicle, abrasion occurs between the fuel and the float, and thereby static electricity is generated. If a member connected to the arm and supporting the permanent magnet is made of a non-conductive material such as resin, electrostatic charges are accumulated in the arm. The electrostatic charges may be discharged for some reasons to a conductive terminal connected to the magnetoresistive element. If this happens, a signal representing the fuel level is disturbed, and detection accuracy of the fuel level gauge is adversely affected.